Helmet



FIG. 1 is a perspective view of a helmet, showing our new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a side elevation view thereof taken from the right of FIG. 2, the opposite side being a mirror image thereof; and,

FIG. 5 is a top plan view thereof.

Some drawings include certain features which are shown in broken lines for illustrative purposes only in order to show environment, and form no part of the claimed design. 

CLAIM The ornamental design for a helmet, as shown and described. 